The present invention relates to a battery tray for supporting batteries for driving an electric vehicle.
Hitherto, an electric vehicle has batteries so as to be driven, the batteries being mounted in the interior space thereof or under the floor of the car body.
If the batteries for driving the vehicle are mounted in the interior space of the vehicle, the interior space of the vehicle is reduced undesirably.
In a case where the batteries are disposed under the floor with a battery tray manufactured by an iron material, the battery tray must have a great floor thickness in order to realize required strength. As a result, the minimum road clearance is affected. Since the iron material requires a jig when the battery tray is mounted, the cost cannot be reduced. Moreover, since a large number of portions of the battery tray must be welded, distortion or the like causes dimension errors to probably take place. Moreover, the manufactured battery tray has excessively heavy weight.
In a case where an Al honey-comb is employed to manufacture a battery tray which is disposed under the floor, the weight and the floor thickness of the battery tray can be reduced. However, the Al honey-comb has a possibility of electric erosion when mounted on an iron frame. Since the Al honey-comb cannot considerably withstand shocks, it is unsuitable to be disposed under the floor which is frequently hit by stones. What is worse, the cost of the Al honey-comb is very high and a great cost is required to machine the same.
In a case where FRP (Fiber Reinforced Plastic) is employed to manufacture a battery tray to be disposed under the floor, the weight is enlarged considerably to support the battery tray. To solve the problem above by reducing the weight, a considerably complicated structure is required, thus resulting in the cost being enlarged excessively.